In wireless networks, PTT systems and group methods generally are a half-duplex communication system where one person transmits and others receive. Push to talk over cellular (PoC) includes PTT on 2.5G, 3G, and/or 4G wireless networks. PTT can utilize Session Initiation Protocol (SIP), Real Time Protocol (RTP), Real Time Control Protocol (RTCP), etc. PTT systems and methods are used in a variety of applications such as, for example, mission critical public safety applications. In various PTT applications, there can be various users that participate in PTT calls outside their associated home server. As such, various conventional network-network interface (NNI) techniques have been developed between servers for handling PTT services. An exemplary NNI is the Open Mobile Alliance (OMA) Push to talk Over Cellular V2.1 (August, 2011), the contents of which are incorporated by reference herein. Another exemplary NNI is the Project 25 Inter-RF Subsystem Interface Protocol(s) (ISSI) defined in TIA-102.BACA-A (January 2009), the contents of which are incorporated by reference herein. OMA PoC V2.1, ISSI, etc. each have disadvantages in supporting large scale group sessions and resource negotiations (e.g., floor control). For example, OMA PoC V2.1 includes media traffic optimization but requires individual RTP/RTCP sessions for each user equipment (UE).
Accordingly, there is a need for enhanced PTT systems and methods with floor control and media traffic optimization.
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The apparatus and method components have been represented where appropriate by conventional symbols in the drawings, showing only those specific details that are pertinent to understanding the embodiments of the present invention so as not to obscure the disclosure with details that will be readily apparent to those of ordinary skill in the art having the benefit of the description herein.